Oddlt enough it seems to have cured itself...at least temporarily
It's a Diplomat (yes, cheap MFI) built-in gas hob. Two weeks ago it was clicking the igniters all on it's own, about once a minute. But only two (left front and right rear) were actually making a spark. Bloody irritating noise.
After a day or so it stopped clicking on it's own. But still only two were sparking. So I gave it a good wash, removed all the baked in foodstuffs, no difference.
Then, magically, after a few more days it's all OK again...
Any idea?